1. Technical Field
This application relates to techniques used in connection with event occurrences, and more particularly in connection with determining noteworthy or significant event occurrences.
2. Description of Related Art
Computer systems may include different resources used by one or more host processors. Resources and host processors in a computer system may be interconnected by one or more communication connections. These resources may include, for example, data storage devices such as those included in the data storage systems manufactured by EMC Corporation. These data storage systems may be coupled to one or more servers or host processors and provide storage services to each host processor. Multiple data storage systems from one or more different vendors may be connected and may provide common data storage for one or more host processors in a computer system.
A host processor may perform a variety of data processing tasks and operations using the data storage system. For example, a host processor may perform basic system I/O operations in connection with data requests, such as data read and write operations.
Host processor systems may store and retrieve data using a storage device containing a plurality of host interface units, disk drives, and disk interface units. The host systems access the storage device through a plurality of channels provided therewith. Host systems provide data and access control information through the channels to the storage device and the storage device provides data to the host systems also through the channels. The host systems do not address the disk drives of the storage device directly, but rather, access what appears to the host systems as a plurality of logical disk units. The logical disk units may or may not correspond to the actual disk drives. Allowing multiple host systems to access the single storage device unit allows the host systems to share data in the device. In order to facilitate sharing of the data on the device, additional software on the data storage systems may also be used.
In connection with data storage systems, or more generally any type of system, events may repetitively occur. If such events occur at a high rate, a system may utilize an undesirable amount of resources processing these event occurrences. Thus, there may be an adverse affect on the ability of the system to have sufficient resources remaining to perform other more typical processing. Such a constant stream of event occurrences may be commonly referred to as an indication storm. The adverse consequences may include, for example, the users of the system experiencing delays in connection with performing other operations while the system is processing the constant stream of event occurrences. Another possible adverse consequence is that reporting on such a constant stream of repeated event occurrences may hinder the ability to diagnose a problem in different ways. For example, since most of the messages regarding event occurrences are those of the constant stream, such messages may obscure an occurrence of any other more important event, or such messages may consume an undesirable amount of a finite resource, such as a buffer, where such messages may be recorded thereby causing possible loss of other more important messages once the finite resource is exhausted.